1393045921 has 4 divisors (see below), whose sum is σ = 1394162500. Its totient is φ = 1391929344.

The previous prime is 1393045919. The next prime is 1393045981. The reversal of 1393045921 is 1295403931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1295403931 = 9391 ⋅137941.

It can be written as a sum of positive squares in 2 ways, for example, as 1091641600 + 301404321 = 33040^2 + 17361^2 .

It is a cyclic number.

It is not a de Polignac number, because 1393045921 - 2¹ = 1393045919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1393045981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 556416 + ... + 558913.

It is an arithmetic number, because the mean of its divisors is an integer number (348540625).

Almost surely, 2^1393045921 is an apocalyptic number.

It is an amenable number.

1393045921 is a deficient number, since it is larger than the sum of its proper divisors (1116579).

1393045921 is a wasteful number, since it uses less digits than its factorization.

1393045921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1116578.

The product of its (nonzero) digits is 29160, while the sum is 37.

The square root of 1393045921 is about 37323.5303930376. The cubic root of 1393045921 is about 1116.8336164534.

The spelling of 1393045921 in words is "one billion, three hundred ninety-three million, forty-five thousand, nine hundred twenty-one".